<!doctype html>
<html>
<head>
<meta charset='UTF-8'><meta name='viewport' content='width=device-width initial-scale=1'>

<link href='https://fonts.loli.net/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext' rel='stylesheet' type='text/css' /><style type='text/css'>html {overflow-x: initial !important;}:root { --bg-color:#ffffff; --text-color:#333333; --select-text-bg-color:#B5D6FC; --select-text-font-color:auto; --monospace:"Lucida Console",Consolas,"Courier",monospace; --title-bar-height:20px; }
.mac-os-11 { --title-bar-height:28px; }
html { font-size: 14px; background-color: var(--bg-color); color: var(--text-color); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; -webkit-font-smoothing: antialiased; }
body { margin: 0px; padding: 0px; height: auto; inset: 0px; font-size: 1rem; line-height: 1.42857; overflow-x: hidden; background: inherit; tab-size: 4; }
iframe { margin: auto; }
a.url { word-break: break-all; }
a:active, a:hover { outline: 0px; }
.in-text-selection, ::selection { text-shadow: none; background: var(--select-text-bg-color); color: var(--select-text-font-color); }
#write { margin: 0px auto; height: auto; width: inherit; word-break: normal; overflow-wrap: break-word; position: relative; white-space: normal; overflow-x: visible; padding-top: 36px; }
#write.first-line-indent p { text-indent: 2em; }
#write.first-line-indent li p, #write.first-line-indent p * { text-indent: 0px; }
#write.first-line-indent li { margin-left: 2em; }
.for-image #write { padding-left: 8px; padding-right: 8px; }
body.typora-export { padding-left: 30px; padding-right: 30px; }
.typora-export .footnote-line, .typora-export li, .typora-export p { white-space: pre-wrap; }
.typora-export .task-list-item input { pointer-events: none; }
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  #write { padding-left: 20px; padding-right: 20px; }
}
#write li > figure:last-child { margin-bottom: 0.5rem; }
#write ol, #write ul { position: relative; }
img { max-width: 100%; vertical-align: middle; image-orientation: from-image; }
button, input, select, textarea { color: inherit; font: inherit; }
input[type="checkbox"], input[type="radio"] { line-height: normal; padding: 0px; }
*, ::after, ::before { box-sizing: border-box; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p, #write pre { width: inherit; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p { position: relative; }
p { line-height: inherit; }
h1, h2, h3, h4, h5, h6 { break-after: avoid-page; break-inside: avoid; orphans: 4; }
p { orphans: 4; }
h1 { font-size: 2rem; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.6rem; }
h4 { font-size: 1.4rem; }
h5 { font-size: 1.2rem; }
h6 { font-size: 1rem; }
.md-math-block, .md-rawblock, h1, h2, h3, h4, h5, h6, p { margin-top: 1rem; margin-bottom: 1rem; }
.hidden { display: none; }
.md-blockmeta { color: rgb(204, 204, 204); font-weight: 700; font-style: italic; }
a { cursor: pointer; }
sup.md-footnote { padding: 2px 4px; background-color: rgba(238, 238, 238, 0.7); color: rgb(85, 85, 85); border-radius: 4px; cursor: pointer; }
sup.md-footnote a, sup.md-footnote a:hover { color: inherit; text-transform: inherit; text-decoration: inherit; }
#write input[type="checkbox"] { cursor: pointer; width: inherit; height: inherit; }
figure { overflow-x: auto; margin: 1.2em 0px; max-width: calc(100% + 16px); padding: 0px; }
figure > table { margin: 0px; }
thead, tr { break-inside: avoid; break-after: auto; }
thead { display: table-header-group; }
table { border-collapse: collapse; border-spacing: 0px; width: 100%; overflow: auto; break-inside: auto; text-align: left; }
table.md-table td { min-width: 32px; }
.CodeMirror-gutters { border-right: 0px; background-color: inherit; }
.CodeMirror-linenumber { user-select: none; }
.CodeMirror { text-align: left; }
.CodeMirror-placeholder { opacity: 0.3; }
.CodeMirror pre { padding: 0px 4px; }
.CodeMirror-lines { padding: 0px; }
div.hr:focus { cursor: none; }
#write pre { white-space: pre-wrap; }
#write.fences-no-line-wrapping pre { white-space: pre; }
#write pre.ty-contain-cm { white-space: normal; }
.CodeMirror-gutters { margin-right: 4px; }
.md-fences { font-size: 0.9rem; display: block; break-inside: avoid; text-align: left; overflow: visible; white-space: pre; background: inherit; position: relative !important; }
.md-fences-adv-panel { width: 100%; margin-top: 10px; text-align: center; padding-top: 0px; padding-bottom: 8px; overflow-x: auto; }
#write .md-fences.mock-cm { white-space: pre-wrap; }
.md-fences.md-fences-with-lineno { padding-left: 0px; }
#write.fences-no-line-wrapping .md-fences.mock-cm { white-space: pre; overflow-x: auto; }
.md-fences.mock-cm.md-fences-with-lineno { padding-left: 8px; }
.CodeMirror-line, twitterwidget { break-inside: avoid; }
svg { break-inside: avoid; }
.footnotes { opacity: 0.8; font-size: 0.9rem; margin-top: 1em; margin-bottom: 1em; }
.footnotes + .footnotes { margin-top: 0px; }
.md-reset { margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: top; background: 0px 0px; text-decoration: none; text-shadow: none; float: none; position: static; width: auto; height: auto; white-space: nowrap; cursor: inherit; -webkit-tap-highlight-color: transparent; line-height: normal; font-weight: 400; text-align: left; box-sizing: content-box; direction: ltr; }
li div { padding-top: 0px; }
blockquote { margin: 1rem 0px; }
li .mathjax-block, li p { margin: 0.5rem 0px; }
li blockquote { margin: 1rem 0px; }
li { margin: 0px; position: relative; }
blockquote > :last-child { margin-bottom: 0px; }
blockquote > :first-child, li > :first-child { margin-top: 0px; }
.footnotes-area { color: rgb(136, 136, 136); margin-top: 0.714rem; padding-bottom: 0.143rem; white-space: normal; }
#write .footnote-line { white-space: pre-wrap; }
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  body, html { border: 1px solid transparent; height: 99%; break-after: avoid; break-before: avoid; font-variant-ligatures: no-common-ligatures; }
  #write { margin-top: 0px; padding-top: 0px; border-color: transparent !important; padding-bottom: 0px !important; }
  .typora-export * { -webkit-print-color-adjust: exact; }
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  .typora-export #write::after { height: 0px; }
  .is-mac table { break-inside: avoid; }
  .typora-export-show-outline .typora-export-sidebar { display: none; }
}
.footnote-line { margin-top: 0.714em; font-size: 0.7em; }
a img, img a { cursor: pointer; }
pre.md-meta-block { font-size: 0.8rem; min-height: 0.8rem; white-space: pre-wrap; background: rgb(204, 204, 204); display: block; overflow-x: hidden; }
p > .md-image:only-child:not(.md-img-error) img, p > img:only-child { display: block; margin: auto; }
#write.first-line-indent p > .md-image:only-child:not(.md-img-error) img { left: -2em; position: relative; }
p > .md-image:only-child { display: inline-block; width: 100%; }
#write .MathJax_Display { margin: 0.8em 0px 0px; }
.md-math-block { width: 100%; }
.md-math-block:not(:empty)::after { display: none; }
.MathJax_ref { fill: currentcolor; }
[contenteditable="true"]:active, [contenteditable="true"]:focus, [contenteditable="false"]:active, [contenteditable="false"]:focus { outline: 0px; box-shadow: none; }
.md-task-list-item { position: relative; list-style-type: none; }
.task-list-item.md-task-list-item { padding-left: 0px; }
.md-task-list-item > input { position: absolute; top: 0px; left: 0px; margin-left: -1.2em; margin-top: calc(1em - 10px); border: none; }
.math { font-size: 1rem; }
.md-toc { min-height: 3.58rem; position: relative; font-size: 0.9rem; border-radius: 10px; }
.md-toc-content { position: relative; margin-left: 0px; }
.md-toc-content::after, .md-toc::after { display: none; }
.md-toc-item { display: block; color: rgb(65, 131, 196); }
.md-toc-item a { text-decoration: none; }
.md-toc-inner:hover { text-decoration: underline; }
.md-toc-inner { display: inline-block; cursor: pointer; }
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.md-toc-h3 .md-toc-inner { margin-left: 4em; }
.md-toc-h4 .md-toc-inner { margin-left: 6em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 .md-toc-inner { margin-left: 10em; }
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  .md-toc-h3 .md-toc-inner { margin-left: 3.5em; }
  .md-toc-h4 .md-toc-inner { margin-left: 5em; }
  .md-toc-h5 .md-toc-inner { margin-left: 6.5em; }
  .md-toc-h6 .md-toc-inner { margin-left: 8em; }
}
a.md-toc-inner { font-size: inherit; font-style: inherit; font-weight: inherit; line-height: inherit; }
.footnote-line a:not(.reversefootnote) { color: inherit; }
.reversefootnote { font-family: ui-monospace, sans-serif; }
.md-attr { display: none; }
.md-fn-count::after { content: "."; }
code, pre, samp, tt { font-family: var(--monospace); }
kbd { margin: 0px 0.1em; padding: 0.1em 0.6em; font-size: 0.8em; color: rgb(36, 39, 41); background: rgb(255, 255, 255); border: 1px solid rgb(173, 179, 185); border-radius: 3px; box-shadow: rgba(12, 13, 14, 0.2) 0px 1px 0px, rgb(255, 255, 255) 0px 0px 0px 2px inset; white-space: nowrap; vertical-align: middle; }
.md-comment { color: rgb(162, 127, 3); opacity: 0.6; font-family: var(--monospace); }
code { text-align: left; vertical-align: initial; }
a.md-print-anchor { white-space: pre !important; border-width: initial !important; border-style: none !important; border-color: initial !important; display: inline-block !important; position: absolute !important; width: 1px !important; right: 0px !important; outline: 0px !important; background: 0px 0px !important; text-decoration: initial !important; text-shadow: initial !important; }
.os-windows.monocolor-emoji .md-emoji { font-family: "Segoe UI Symbol", sans-serif; }
.md-diagram-panel > svg { max-width: 100%; }
[lang="flow"] svg, [lang="mermaid"] svg { max-width: 100%; height: auto; }
[lang="mermaid"] .node text { font-size: 1rem; }
table tr th { border-bottom: 0px; }
video { max-width: 100%; display: block; margin: 0px auto; }
iframe { max-width: 100%; width: 100%; border: none; }
.highlight td, .highlight tr { border: 0px; }
mark { background: rgb(255, 255, 0); color: rgb(0, 0, 0); }
.md-html-inline .md-plain, .md-html-inline strong, mark .md-inline-math, mark strong { color: inherit; }
.md-expand mark .md-meta { opacity: 0.3 !important; }
mark .md-meta { color: rgb(0, 0, 0); }
@media print {
  .typora-export h1, .typora-export h2, .typora-export h3, .typora-export h4, .typora-export h5, .typora-export h6 { break-inside: avoid; }
}
.md-diagram-panel .messageText { stroke: none !important; }
.md-diagram-panel .start-state { fill: var(--node-fill); }
.md-diagram-panel .edgeLabel rect { opacity: 1 !important; }
.md-fences.md-fences-math { font-size: 1em; }
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.md-fences-advanced:not(.md-focus) { background: inherit; }
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.typora-export-sidebar { width: 300px; font-size: 0.8rem; margin-top: 80px; margin-right: 18px; }
.typora-export-show-outline #write { --webkit-flex:2; flex: 2 1 0%; }
.typora-export-sidebar .outline-content { position: fixed; top: 0px; max-height: 100%; overflow: hidden auto; padding-bottom: 30px; padding-top: 60px; width: 300px; }
@media screen and (max-width: 1024px) {
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}
@media screen and (max-width: 800px) {
  .typora-export-sidebar { display: none; }
}
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.outline-content ul { margin-top: 0px; margin-bottom: 0px; }
.outline-content strong { font-weight: 400; }
.outline-expander { width: 1rem; height: 1.42857rem; position: relative; display: table-cell; vertical-align: middle; cursor: pointer; padding-left: 4px; }
.outline-expander::before { content: ""; position: relative; font-family: Ionicons; display: inline-block; font-size: 8px; vertical-align: middle; }
.outline-item { padding-top: 3px; padding-bottom: 3px; cursor: pointer; }
.outline-expander:hover::before { content: ""; }
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.outline-h2 > .outline-item { padding-left: 1em; }
.outline-h3 > .outline-item { padding-left: 2em; }
.outline-h4 > .outline-item { padding-left: 3em; }
.outline-h5 > .outline-item { padding-left: 4em; }
.outline-h6 > .outline-item { padding-left: 5em; }
.outline-label { cursor: pointer; display: table-cell; vertical-align: middle; text-decoration: none; color: inherit; }
.outline-label:hover { text-decoration: underline; }
.outline-item:hover { border-color: rgb(245, 245, 245); background-color: var(--item-hover-bg-color); }
.outline-item:hover { margin-left: -28px; margin-right: -28px; border-left: 28px solid transparent; border-right: 28px solid transparent; }
.outline-item-single .outline-expander::before, .outline-item-single .outline-expander:hover::before { display: none; }
.outline-item-open > .outline-item > .outline-expander::before { content: ""; }
.outline-children { display: none; }
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.outline-item-open > .outline-children { display: block; }
.typora-export .outline-item { padding-top: 1px; padding-bottom: 1px; }
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.typora-export-collapse-outline .outline-item-open > .outline-children, .typora-export-no-collapse-outline .outline-children { display: block; }
.typora-export-no-collapse-outline .outline-expander::before { content: "" !important; }
.typora-export-show-outline .outline-item-active > .outline-item .outline-label { font-weight: 700; }
.md-inline-math-container mjx-container { zoom: 0.95; }
mjx-container { break-inside: avoid; }


.CodeMirror { height: auto; }
.CodeMirror.cm-s-inner { background: inherit; }
.CodeMirror-scroll { overflow: auto hidden; z-index: 3; }
.CodeMirror-gutter-filler, .CodeMirror-scrollbar-filler { background-color: rgb(255, 255, 255); }
.CodeMirror-gutters { border-right: 1px solid rgb(221, 221, 221); background: inherit; white-space: nowrap; }
.CodeMirror-linenumber { padding: 0px 3px 0px 5px; text-align: right; color: rgb(153, 153, 153); }
.cm-s-inner .cm-keyword { color: rgb(119, 0, 136); }
.cm-s-inner .cm-atom, .cm-s-inner.cm-atom { color: rgb(34, 17, 153); }
.cm-s-inner .cm-number { color: rgb(17, 102, 68); }
.cm-s-inner .cm-def { color: rgb(0, 0, 255); }
.cm-s-inner .cm-variable { color: rgb(0, 0, 0); }
.cm-s-inner .cm-variable-2 { color: rgb(0, 85, 170); }
.cm-s-inner .cm-variable-3 { color: rgb(0, 136, 85); }
.cm-s-inner .cm-string { color: rgb(170, 17, 17); }
.cm-s-inner .cm-property { color: rgb(0, 0, 0); }
.cm-s-inner .cm-operator { color: rgb(152, 26, 26); }
.cm-s-inner .cm-comment, .cm-s-inner.cm-comment { color: rgb(170, 85, 0); }
.cm-s-inner .cm-string-2 { color: rgb(255, 85, 0); }
.cm-s-inner .cm-meta { color: rgb(85, 85, 85); }
.cm-s-inner .cm-qualifier { color: rgb(85, 85, 85); }
.cm-s-inner .cm-builtin { color: rgb(51, 0, 170); }
.cm-s-inner .cm-bracket { color: rgb(153, 153, 119); }
.cm-s-inner .cm-tag { color: rgb(17, 119, 0); }
.cm-s-inner .cm-attribute { color: rgb(0, 0, 204); }
.cm-s-inner .cm-header, .cm-s-inner.cm-header { color: rgb(0, 0, 255); }
.cm-s-inner .cm-quote, .cm-s-inner.cm-quote { color: rgb(0, 153, 0); }
.cm-s-inner .cm-hr, .cm-s-inner.cm-hr { color: rgb(153, 153, 153); }
.cm-s-inner .cm-link, .cm-s-inner.cm-link { color: rgb(0, 0, 204); }
.cm-negative { color: rgb(221, 68, 68); }
.cm-positive { color: rgb(34, 153, 34); }
.cm-header, .cm-strong { font-weight: 700; }
.cm-del { text-decoration: line-through; }
.cm-em { font-style: italic; }
.cm-link { text-decoration: underline; }
.cm-error { color: red; }
.cm-invalidchar { color: red; }
.cm-constant { color: rgb(38, 139, 210); }
.cm-defined { color: rgb(181, 137, 0); }
div.CodeMirror span.CodeMirror-matchingbracket { color: rgb(0, 255, 0); }
div.CodeMirror span.CodeMirror-nonmatchingbracket { color: rgb(255, 34, 34); }
.cm-s-inner .CodeMirror-activeline-background { background: inherit; }
.CodeMirror { position: relative; overflow: hidden; }
.CodeMirror-scroll { height: 100%; outline: 0px; position: relative; box-sizing: content-box; background: inherit; }
.CodeMirror-sizer { position: relative; }
.CodeMirror-gutter-filler, .CodeMirror-hscrollbar, .CodeMirror-scrollbar-filler, .CodeMirror-vscrollbar { position: absolute; z-index: 6; display: none; outline: 0px; }
.CodeMirror-vscrollbar { right: 0px; top: 0px; overflow: hidden; }
.CodeMirror-hscrollbar { bottom: 0px; left: 0px; overflow: auto hidden; }
.CodeMirror-scrollbar-filler { right: 0px; bottom: 0px; }
.CodeMirror-gutter-filler { left: 0px; bottom: 0px; }
.CodeMirror-gutters { position: absolute; left: 0px; top: 0px; padding-bottom: 10px; z-index: 3; overflow-y: hidden; }
.CodeMirror-gutter { white-space: normal; height: 100%; box-sizing: content-box; padding-bottom: 30px; margin-bottom: -32px; display: inline-block; }
.CodeMirror-gutter-wrapper { position: absolute; z-index: 4; background: 0px 0px !important; border: none !important; }
.CodeMirror-gutter-background { position: absolute; top: 0px; bottom: 0px; z-index: 4; }
.CodeMirror-gutter-elt { position: absolute; cursor: default; z-index: 4; }
.CodeMirror-lines { cursor: text; }
.CodeMirror pre { border-radius: 0px; border-width: 0px; background: 0px 0px; font-family: inherit; font-size: inherit; margin: 0px; white-space: pre; overflow-wrap: normal; color: inherit; z-index: 2; position: relative; overflow: visible; }
.CodeMirror-wrap pre { overflow-wrap: break-word; white-space: pre-wrap; word-break: normal; }
.CodeMirror-code pre { border-right: 30px solid transparent; width: fit-content; }
.CodeMirror-wrap .CodeMirror-code pre { border-right: none; width: auto; }
.CodeMirror-linebackground { position: absolute; inset: 0px; z-index: 0; }
.CodeMirror-linewidget { position: relative; z-index: 2; overflow: auto; }
.CodeMirror-wrap .CodeMirror-scroll { overflow-x: hidden; }
.CodeMirror-measure { position: absolute; width: 100%; height: 0px; overflow: hidden; visibility: hidden; }
.CodeMirror-measure pre { position: static; }
.CodeMirror div.CodeMirror-cursor { position: absolute; visibility: hidden; border-right: none; width: 0px; }
.CodeMirror div.CodeMirror-cursor { visibility: hidden; }
.CodeMirror-focused div.CodeMirror-cursor { visibility: inherit; }
.cm-searching { background: rgba(255, 255, 0, 0.4); }
span.cm-underlined { text-decoration: underline; }
span.cm-strikethrough { text-decoration: line-through; }
.cm-tw-syntaxerror { color: rgb(255, 255, 255); background-color: rgb(153, 0, 0); }
.cm-tw-deleted { text-decoration: line-through; }
.cm-tw-header5 { font-weight: 700; }
.cm-tw-listitem:first-child { padding-left: 10px; }
.cm-tw-box { border-style: solid; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-color: inherit; border-top-width: 0px !important; }
.cm-tw-underline { text-decoration: underline; }
@media print {
  .CodeMirror div.CodeMirror-cursor { visibility: hidden; }
}


:root {
    --side-bar-bg-color: #fafafa;
    --control-text-color: #777;
}

@include-when-export url(https://fonts.loli.net/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext);

/* open-sans-regular - latin-ext_latin */
  /* open-sans-italic - latin-ext_latin */
    /* open-sans-700 - latin-ext_latin */
    /* open-sans-700italic - latin-ext_latin */
  html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: "Open Sans","Clear Sans", "Helvetica Neue", Helvetica, Arial, 'Segoe UI Emoji', sans-serif;
    color: rgb(51, 51, 51);
    line-height: 1.6;
}

#write {
    max-width: 860px;
  	margin: 0 auto;
  	padding: 30px;
    padding-bottom: 100px;
}

@media only screen and (min-width: 1400px) {
	#write {
		max-width: 1024px;
	}
}

@media only screen and (min-width: 1800px) {
	#write {
		max-width: 1200px;
	}
}

#write > ul:first-child,
#write > ol:first-child{
    margin-top: 30px;
}

a {
    color: #4183C4;
}
h1,
h2,
h3,
h4,
h5,
h6 {
    position: relative;
    margin-top: 1rem;
    margin-bottom: 1rem;
    font-weight: bold;
    line-height: 1.4;
    cursor: text;
}
h1:hover a.anchor,
h2:hover a.anchor,
h3:hover a.anchor,
h4:hover a.anchor,
h5:hover a.anchor,
h6:hover a.anchor {
    text-decoration: none;
}
h1 tt,
h1 code {
    font-size: inherit;
}
h2 tt,
h2 code {
    font-size: inherit;
}
h3 tt,
h3 code {
    font-size: inherit;
}
h4 tt,
h4 code {
    font-size: inherit;
}
h5 tt,
h5 code {
    font-size: inherit;
}
h6 tt,
h6 code {
    font-size: inherit;
}
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</style><title>Doris 与 ClickHouse 的深度对比</title>
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<div id='write'  class=''><h1 id='doris-与-clickhouse-的深度对比'><span>Doris 与 ClickHouse 的深度对比</span></h1><h2 id='背景'><span>背景</span></h2><ul><li><a href='https://so.csdn.net/so/search?q=Apache&amp;spm=1001.2101.3001.7020'><span>Apache</span></a><span> Doris是由百度贡献的开源MPP分析型数据库产品，亚秒级查询响应时间，支持实时数据分析；分布式架构简洁，易于运维，可以支持10PB以上的超大数据集；可以满足多种数据分析需求，例如固定历史报表，实时数据分析，交互式数据分析和探索式数据分析等</span></li><li><a href='https://so.csdn.net/so/search?q=ClickHouse&amp;spm=1001.2101.3001.7020'><span>ClickHouse</span></a><span>是俄罗斯的搜索公司Yandex开源的MPP架构的分析引擎，号称比事务数据库快100-1000倍，团队有计算机体系结构的大牛，最大的特色是高性能的向量化执行引擎，而且功能丰富、可靠性高。</span></li><li><span>京东当前都在大范围使用这两种分析引擎，总集群规模超过3000台服务器，涵盖了交易、流量、线下和大屏等各类场景。本文将结合京东团队的调研成果和几年的实践经验，对Doris和ClickHouse这两种分析引擎进行深入对比，验证广为流传的说法，供大家在场景选型或内核研发时提供一个参考，另外对于两者社区规划提供一定的借鉴。</span></li></ul><h2 id='差异和选择建议'><span>差异和选择建议</span></h2><h4 id='doris'><span>Doris</span></h4><ul><li><span>用更简单，如建表更简单，SQL标准支持更好， Join性能更好，导数功能更强大</span></li><li><span>运维更简单，如灵活的扩缩容能力，故障节点自动恢复，社区提供的支持更好</span></li><li><a href='https://so.csdn.net/so/search?q=分布式&amp;spm=1001.2101.3001.7020'><span>分布式</span></a><span>更强，支持事务和幂等性导数，物化视图自动聚合，查询自动路由，全面元数据管理</span></li></ul><h4 id='clickhouse'><span>ClickHouse</span></h4><ul><li><span>性能更佳，导入性能和单表查询性能更好，同时可靠性更好</span></li><li><span>功能丰富，非常多的表引擎，更多类型和函数支持，更好的聚合函数以及庞大的优化参数选项</span></li><li><span>集群管理工具更多，更好多租户和配额管理，灵活的集群管理，方便的集群间迁移工具</span></li></ul><h3 id='对比差异'><span>对比差异</span></h3><ul><li><span>ClickHouse 适用于 业务场景复杂数据规模巨大，希望投入研发力量做定制开发</span></li><li><span>Doris提供一站式的分析解决方案，少量投入研发资源</span></li></ul><p><span>另外， Doris源自在线广告系统，偏交易系统数据分析；ClickHouse起源于网站流量分析服务，偏互联网数据分析，但是这两类场景这两个引擎都可以覆盖。如果说两者不那么强的地方，ClickHouse的问题是使用门槛高、运维成本高和分布式能力太弱，需要较多的定制化和较深的技术实力，Doris的问题是性能差一些可靠性差一些，下面就深入分析两者的差异。</span></p><p>&nbsp;</p><h2 id='架构分析'><span>架构分析</span></h2><p><span>从部署运维、分布式能力、数据导入、查询、存储和使用成本等方面进行对比，这部分会涉及到内核中的设计原理、方案和实现</span></p><h3 id='部署运维'><span>部署运维</span></h3><h4 id='部署及日常运维'><span>部署及日常运维</span></h4><ul><li><span>Doris的部署图，JDBC指接入协议，DNS是域名和请求分发系统。Managerment Panel是管控面。Frontend指前端模块简称FE，包含了SQL解析、查询计划、计划调度、元数据管理等功能，Backend指后端模块简称BE负责存储层、数据读取和写入，另外还有一个BrokerLoad导数组件最好是单独部署。所以，Doris一般只需要FE和BE两个组件。</span></li></ul><p><img src="C:\Users\cheil\Desktop\Doris&amp;ClickHouse对比分析\Doris 部署架构图 (1).png" referrerpolicy="no-referrer" alt="Doris 部署架构图 (1)"></p><p><span>  </span></p><ul><li><span>ClickHouse的部署架构图，ClickHouse本身只有一个模块，就是ClickHouse Server，周边有两个模块，如ClickHouseProxy主要是转发请求、配额限制和容灾等，ZooKeeper这块负责分布式DDL和副本间数据同步，ClickHouseCopier负责集群和数据迁移，ClickHouse一般需要Server、ZooKeeper和CHProxy三个组件。</span></li></ul><p><img src="C:\Users\cheil\Desktop\Doris&amp;ClickHouse对比分析\ClickHouse 部署图.svg" referrerpolicy="no-referrer" alt="ClickHouse 部署图"></p><ul><li><span>日常运维如更新版本、更改配置文件两者都需要依赖Ansible或者SaltStack来进行批量更新。两者都有部分配置文件可以热更新，不用重启节点，而且有Session相关参数可以设置可以覆盖配置文件。Doris有较多的SQL命令协助运维，比如增加节点，Doris中Add Backend即可，ClickHouse中需要更改配置文件并下发到各个节点上。</span></li><li><span>部署时注意将</span><strong><span>zk</span></strong><span> 集群独立于 </span><strong><span>ClickHouse</span></strong><span> 避免在高并发场景下的资源争抢带来的性能问题</span></li></ul><h4 id='租户管理'><span>租户管理</span></h4><figure><table><thead><tr><th style='text-align:center;' ><span>features</span></th><th style='text-align:center;' ><span>Doris</span></th><th style='text-align:center;' ><span>ClickHouse</span></th></tr></thead><tbody><tr><td style='text-align:center;' ><strong><span>RBAC</span></strong></td><td style='text-align:center;' ><strong><span>部分</span></strong></td><td style='text-align:center;' ><strong><span>是</span></strong></td></tr><tr><td style='text-align:center;' ><span>行级别权限</span></td><td style='text-align:center;' ><span>否</span></td><td style='text-align:center;' ><span>是</span></td></tr><tr><td style='text-align:center;' ><span>查询线程限制</span></td><td style='text-align:center;' ><span>是</span></td><td style='text-align:center;' ><span>是</span></td></tr><tr><td style='text-align:center;' ><strong><span>查询内存限制</span></strong></td><td style='text-align:center;' ><span>是</span></td><td style='text-align:center;' ><strong><span>是</span></strong></td></tr><tr><td style='text-align:center;' ><span>用户查询超时限制</span></td><td style='text-align:center;' ><span>是</span></td><td style='text-align:center;' ><span>是</span></td></tr><tr><td style='text-align:center;' ><span>用户查询行数限制</span></td><td style='text-align:center;' ><span>否</span></td><td style='text-align:center;' ><span>是</span></td></tr><tr><td style='text-align:center;' ><strong><span>用户内存限制</span></strong></td><td style='text-align:center;' ><span>是（2g）</span></td><td style='text-align:center;' ><strong><span>是</span></strong></td></tr><tr><td style='text-align:center;' ><span>用户并发限制</span></td><td style='text-align:center;' ><span>是</span></td><td style='text-align:center;' ><span>是</span></td></tr><tr><td style='text-align:center;' ><strong><span>用户查询数量限制</span></strong></td><td style='text-align:center;' ><strong><span>否</span></strong></td><td style='text-align:center;' ><strong><span>是</span></strong></td></tr><tr><td style='text-align:center;' ><span>审计日志</span></td><td style='text-align:center;' ><span>日志</span></td><td style='text-align:center;' ><span>数据表</span></td></tr></tbody></table></figure><p><strong><span>综上表格 </span></strong><span> </span><strong><span>ClickHouse</span></strong><span>的权限和</span><strong><span>Quota</span></strong><span>的粒度更细，可以很方便的支持多租户使用共享集群。</span></p><ul><li><span>可以设置查询内存、查询线程数量、查询超时等，以便来限制查询的大小；</span></li><li><span>同时结合查询并发和一定时间窗口内的查询数量，以便来控制查询数量。</span></li><li><span>多租户的方案，对发展中的业务非常友好，因为使用共享集群资源，可以快速动态调整配额，如果是独占集群资源利用率不高、扩容相对麻烦</span></li></ul><h4 id='集群迁移'><span>集群迁移</span></h4><ul><li><p><span>Doris</span></p><p><img src="C:\Users\cheil\Desktop\Doris&amp;ClickHouse对比分析\Doris 集群备份&amp;迁移.png" referrerpolicy="no-referrer" alt="Doris 集群备份&amp;迁移"></p></li><li><p><span>ClickHouse</span></p><p><img src="C:\Users\cheil\Desktop\Doris&amp;ClickHouse对比分析\ClickHouse 备份&amp;迁移.png" referrerpolicy="no-referrer" alt="ClickHouse 备份&amp;迁移"></p></li></ul><h4 id='集群扩容缩容'><span>集群扩容/缩容</span></h4><ul><li><p><span>Doris支持集群的在线动态扩缩容，通过内置的SQL命令</span></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="sql"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="sql"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"> <span class="cm-keyword">alter</span> <span class="cm-builtin">system</span> <span class="cm-keyword">add</span>/decomission backends </span></pre></div></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 23px;"></div><div class="CodeMirror-gutters" style="display: none; height: 23px;"></div></div></div></pre><p>&nbsp;</p><p><span>即可进行节点的扩缩容，数据均衡的粒度是tablet，每个tablet大概是数百兆，扩容后表的tablet会自动拷贝到新的BE节点，如果在线扩容，应该小批量去增加BE，避免过于剧烈导致集群不稳定。</span></p><p><img src="C:\Users\cheil\Desktop\Doris&ClickHouse对比分析\Doris扩容缩容.svg" alt="Doris扩容缩容" style="zoom: 300%;" /></p></li><li><p><span>ClickHouse的扩容缩容复杂且繁琐，目前做不到自动在线操作，需要自研工具支持。扩容时需要部署新的节点，添加新分片和副本到配置文件中，并在新节点上创建元数据，如果是扩副本数据会自动均衡，如果是扩分片，需要手工去做均衡，或自研相关工具，让均衡自动进行。</span></p></li></ul><h3 id='分布式能力'><span>分布式能力</span></h3><h4 id='分布式协议和高可用'><span>分布式协议和高可用</span></h4><ul><li><p><span>Doris在FrontEnd中包含元数据的管理能力，内置了BerkeleyDB JE HA组件，包含选举策略和副本数据同步，提供了FE的高可用方案。FE中管理的元数据也非常丰富，包含节点、集群、库、表和用户信息，以及分区、Tablet等数据信息，也包含事务、后台任务、DDL操作和导数相关任务等信息。</span></p><p><span>Doris的 FrontEnd可以部署3个Follwer + n个Oberserver（n&gt;=0）的方式来实现元数据和访问连接的高可用，Follower参与选主，在有Follwer宕机时，会自动的选举出新节点保证读写高可用，Observer是只读的扩展节点，可以水平扩展实现读的扩展。BE通过多副本来实现高可用，一般来说也采取默认的三副本，写入的时候采用Quroum协议保证数据一致性。</span></p><p><span>Doris的元数据和数据多副本存储的，能自动复制具有自动灾备的能力，服务挂了可以自动重启，坏一块盘数据自动均衡，小范围的节点宕机不会影响集群对外的服务，但宕机后数据均衡过程会消耗集群资源，引发短时间的负载过高</span></p></li></ul><p><img src="C:\Users\cheil\Desktop\Doris&amp;ClickHouse对比分析\Doris 选举及数据同步.png" referrerpolicy="no-referrer" alt="Doris 选举及数据同步"></p><ul><li><p><span>ClickHouse目前版本是基于ZooKeeper来存储元数据，包含分布式的DDL、表和数据Part信息，从元数据丰富程度来说稍弱，因为存储了大量细粒度的文件信息，导致ZooKeeper经常出现性能瓶颈，社区也有基于Raft协议的改进计划。ClickHouse依赖Zookeeper来实现数据的高可用，Zookeeper带来额外的运维复杂性的同时也有性能问题。</span></p><p><span>ClickHouse没有集中的元数据管理，每个节点分别管理，高可用一般依赖业务方来实现。ClickHouse中某个副本节点宕机，对查询和分布式表的导入没有影响，本地表导入要在导数程序中做灾备方案比如选择健康的副本，对DDL操作是有影响的，需要及时处理</span></p><p>&nbsp;</p></li><li><p><img src="C:\Users\cheil\Downloads\ClickHouse选举及数据同步.png" alt="ClickHouse选举及数据同步" style="zoom:150%;" /></p></li><li><p><strong><span>总结：在分布式能力这块，Doris在内核侧已经实现，使用的代价更低；而ClickHouse需要依赖于外部配套的措施去保障，使用成本较高。</span></strong></p></li></ul><h4 id='数据库事务支持'><span>数据库事务支持</span></h4><ul><li><p><span>ACID指事务的原子性、一致性、隔离性和持久化。</span></p></li><li><p><span>OLAP的事务体现:</span></p><ul><li><span>导数，需要保证导数的原子性，同时也要保证明细数据和物化视图的数据一致性；</span></li><li><span>元数据的变更，需要保证所有节点的元数据统一变更的强一致性；</span></li><li><span>在节点间做数据均衡时，需要保证数据的一致性。</span></li></ul></li><li><p><span>Doris提供了导入的事务支持，可以保证导数的幂等性，比如数据导入的原子性，如果有其他错误会自动回滚，同时相同标签的数据不会重复导入。基于导入事务的功能，Doris还实现了Flink-connector这样的外部组件可以实现数据导入不丢不重。两者均不支持通用TP场景中的BEGIN/END/COMMIT语义的事务，很明显有事务支持的Doris比无事务支持的ClickHouse要节省很多开发成本，因为在ClickHouse中，这一切都需要外部导数程序来保证。</span></p></li><li><p><span>ClickHouse不支持事务，需要在外部去做各种校验和检查，在导数这块能保证100万以内的原子性，但是不保证一致性，比如要更新某些字段或者更新物化视图，这个操作是后台异步的，需要显示指定关键字FINAL来查询最终数据，而且其他操作没有事务支持。</span></p></li><li><p><span>DDL操作两者都是异步的，但是Doris能保证各个节点元数据的一致性，但ClickHouse中保证不了，会出现局部节点元数据和其他节点不一致的情况。</span></p></li></ul><h4 id='数据导入'><span>数据导入</span></h4><p>&nbsp;</p><ul><li><p><span>Doris中有RoutineLoad、BrokerLoad和StreamLoad等丰富内置的导数方式，这些功能非常好用，虽然无法处理复杂的ETL逻辑，但是支持简单过滤和转换函数，也能容忍少量的数据异常，同时支持ACID和导数幂等性。</span></p><ul><li><span>Routineload支持消费Kafka的实时数据，按每批条数、导入间隔和并发数等设置导数参数，用于实时数据的导入；</span></li><li><span>Brokerload支持从HDFS上导入数据文件，用于离线导数，速度不是很快；</span></li><li><span>Streamload是导数的底层接口，更加高级的功能可以外部程序处理后通过Steamload来导入。</span></li></ul></li></ul></div></div>
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